We present a simple algorithm which maintains the topological order of a directed acyclic graph with $n$ nodes under an online edge insertion sequence in $\O(n^{2.75})$ time, independent of the number of edges $m$ inserted. For dense DAGs, this is an improvement over the previous best result of $\O(\min\{m^{\frac{3}{2}} \log{n}, m^{\frac{3}{2}} + n^2 \log{n}\})$ by Katriel and Bodlaender. We also provide an empirical comparison of our algorithm with other algorithms for online topological sorting.